GM Service Manual Online
For 1990-2009 cars only

Interior Lamps

The interior lighting system includes the following components:

    • The instrument panel lamp dimmer
    • The ashtray illumination lamp
    • The cigar lighter illumination lamp
    • The dome lamp
    • The map lamp
    • The rear compartment lamp

I/P Lamp Dimmer

Voltage is supplied to the I/P lamp dimmer and the illumination lamps when the light switch is in the PARK or HEAD position. The solid state dimmer controls the amount of ground provided to the lamps. The solid state dimmer is grounded to G200 through the Left instrument panel junction block. All of the interior displays are grounded to G200. The intensity of the instrument panel and instrument cluster assembly lamps is controlled by the I/P lamp dimmer located on the left side of the instrument panel. The parking lamps or headlamps must be activated for the instrument panel and instrument cluster assembly lamps to be illuminated. When the parking lamps or headlamps are activated, rotating the I/P lamp dimmer counterclockwise will decrease the instrument cluster assembly, rear window defogger switch, heater control assembly, ashtray and cigar lighter lamps illumination. Illumination of the radio display will revert from 100 percent to the setting of the IP lamp dimmer.

Cigar Lighter Illumination Lamp

The cigar lighter illumination lamp lights whenever the parking lamps or headlamps are activated. The cigar lighter illumination lamp bulb socket is attached to the cigar lighter. Refer to Cigarette Lighter Housing Replacement - Floor Console for cigar lighter removal and installation procedures.

Dome Lamp

The dome lamp is located in the center of the headliner. The dome lamp consists of a clear lens, the dome lamp bulb and a three position slide switch. The slide switch has the following three detent positions:

    • OFF
    • DOOR
    • ON

Power comes from the dome fuse, through the Left Instrument Panel Junction Block, and finally to the dome lamp. When the switch is in the OFF position, the dome lamp will not light. When the dome lamp switch is in the DOOR position, the lamp will light when any door is open. The lamp will remain on until all of the doors are closed. When the dome lamp switch is placed in the ON position, it provides a path to ground to the dome lamp and the lamp will illuminate.

Keyless Entry Interior Illumination

Power comes from the dome fuse, through the Left Instrument Panel Junction Block and finally to the dome lamp. When the transmitter activates the keyless entry system it causes the multifunction alarm module to provide ground to the dome lamp, and the lamp will illuminate.

Map Lamp (w/o Sunroof)

On vehicles equipped with a power sunroof, a map lamp is incorporated into the power sunroof switch. The map lamp consists of the following components:

    • The map lamp bulb
    • A clear lens
    • A two-position push switch

Power comes from the dome fuse, through the left instrument panel junction block and then finally to the courtesy/reading lamp. When the light switch is depressed to the ON position, it provides power to the courtesy/reading lamp. Current flows through the lamp and then continues to G200 and G201. Pushing the switch a second time turns the map lamp off.

Rear Dome Lamp

Power comes from the dome fuse, through the left instrument panel junction block and finally to the rear dome lamp. When the rear tailgate is opened the rear compartment lamp switch closes providing a path to ground. With ground and power supplied the lamp will illuminate.

Interior Lighting Customize Parameters (Scan Tool)

The interior lighting can be customized according to the customer preference.

Important: 

   • Before attempting to customize vehicle settings, confirm whether it is possible to make the change that the customer has requested.
   • Be sure to record the current settings before customizing.
   • Before troubleshooting the lighting system, pay attention because there is a possibility that a function has been disabled by customizing. If the wireless operation does not function, check that the wireless operation has not been disabled by customizing, then perform troubleshooting.

  1. Turn the ignition OFF.
  2. Connect the scan tool.
  3. Turn the scan tool ON, and select the customize setting for interior lighting.
  4. Select the setting by referring to the following table:

Display

Default

Contents

Setting

Lighting Time

15 seconds

Changes the lighting time of the interior light after closing all of the doors. (It will quickly fade out in case of turning the ignition switch ON.)

7.5 seconds, 15 seconds or 30 seconds

Illumination when ACC OFF

ON

Lights up the interior light when the ignition switch is turned from ACC or ON to OFF.

ON / OFF

Illumination ON with door key unlock (if equipped with power door lock control system)

ON

Lights up the interior light when a door is unlocked.

ON / OFF